Diagnostic Ultrasound - Abdomen and Pelvis

Hemorrhagic Cyst
TERMINOLOGY
Abbreviations
• Hemorrhagic cyst (HC)
Definitions
• Hemorrhage into cystic space in ovarian parenchyma
○ Most common at time of ovulation → hemorrhagic
corpus luteum (HCL)
○ May occur into follicular cyst
○ Acute hemorrhage may occur into established
endometrioma
IMAGING
General Features
• Best diagnostic clue
○ Avascular hypoechoic ovarian "mass" with fine lacy
interstices
• Location
○ Intraovarian
• Size
○ Variable, up to 8 cm diameter
Ultrasonographic Findings
• Grayscale ultrasound
○ Lacy interstices due to fibrin strands are characteristic of
acute clot
○ May appear as mixed or variable echogenicity mass
– Clot retraction → echogenic clot with surrounding cyst
fluid
– Clot fragmentation → angular/concave margins of clot
fragments
□ Fragments adhere to cyst wall
□ Float in fluid component
□ Jelly-like motion with transducer compression
○ ~ 90% of hemorrhagic cysts have fibrin strands or
retracting clot
○ 92% show increased through transmission
– Indicates "cystic" nature even though initial
assessment may suggest solid mass
○ As clot resorbs, HC appears more like simple cyst
○ Majority resorb quickly and leave no sequela on 6-12
week follow-up scans
○ HC may rupture
– Look for echogenic fluid in cul-de-sac
– With significant hemorrhage may see
hemoperitoneum
□ Check for fluid in hepatorenal fossa/subphrenic
spaces, which indicates large amount of
hemoperitoneum
○ Cyst wall often appears thick
• Color Doppler
○ Clot is avascular
○ May see increased flow at margins of corpus luteum:
"Ring of fire" appearance
○ Look for flow in ovarian parenchyma stretched around
hemorrhagic cyst
CT Findings
• Cyst may appear simple on CT
• Fluid-fluid level or high-attenuation material may be seen in
HC
• May show ring enhancement
MR Findings
• T1WI
○ Typically intermediate to high signal blood products with
no loss of signal on FS images
– In 1 study, however, 64% of 22 confirmed HC were
hypointense on T1-weighted images
– 18% were also hyperintense on T2-weighted images
○ Hematocrit effect: High signal layering blood akin to
sonographic fluid-fluid level
• T2WI
○ Typically intermediate to low signal
Imaging Recommendations
• Best imaging tool
○ Transvaginal US
DIFFERENTIAL DIAGNOSIS
Endometrioma
• Uniform low-level internal echoes from blood breakdown
products rather than lacy fibrin strands in clot
• Walls often contain punctate high echogenic foci
• More likely to have history of chronic pelvic pain
• Will not change much on follow-up
○ HC would be expected to resolve or decrease
significantly in size
• Occasionally acute bleed into endometrioma, may produce
confusing picture
○ Follow-up will show resolution of acute clot with
persistent background endometrioma
Solid Ovarian Mass
• Papillary projections more likely than angular fragments
• Solid masses reflect sound equally with ovarian
parenchyma
○ No increased through transmission
• Internal vascularity with Doppler interrogation
Torsion
• Tender, enlarged ovary with peripheral follicles,
parenchymal inhomogeneity, and abnormal position
• Variable vascularity: Low-pressure venous system affected
earlier than arterial
Ectopic Pregnancy
• Positive pregnancy test
• Hemorrhagic extraovarian adnexal mass
• Use real-time observation during transducer pressure
○ Ovary will "slide" separately from adnexal mass
○ Intraovarian mass moves with ovary
• May see "ring of fire" sign of increased flow in trophoblastic
tissue
○ Make sure it is extraovarian and not around corpus
luteum within ovary
○ Not all ectopics demonstrate this sign
Pelvic Abscess
• Febrile patient
Diagnoses: Female Pelvis
805